configure.ac, NEWS.adoc: warn if nobody or nogroup end up being used for a build [#3173]

Signed-off-by: Jim Klimov <jimklimov+nut@gmail.com>

Author: jimklimov

NEWS.adoc

@@ -266,7 +266,8 @@ several `FSD` notifications into one executed action. [PR #3097]
  - The `configure` script would now probe (if it can) the operating systems for
    more user and group account names, such as `upsmon`, `nutmon`, `ups`, `nut`
    (last hit wins, separately for user and groups accounts) settling on one of
-   those if detected instead of `nobody` (and optionally `nogroup`). [#3173]
+   those if detected instead of `nobody` (and optionally `nogroup`). It would
+   also warn if `nobody` or `nogroup` end up being used for a build. [#3173]
 
  - Updated `make spellcheck` to help avoid asciidoc admonition blocks with
    visually invalid sentences (after rendering as a box in HTML or PDF). [#3077]

configure.ac

@@ -6950,6 +6950,12 @@ AS_IF([test -s "${ABS_TOP_SRCDIR}/install-sh" && ${GREP} -w MKDIRPROG "${ABS_TOP
 	])
 ])
 
+AS_IF([test x"${RUN_AS_USER}" = xnobody || test x"${RUN_AS_GROUP}" = xnobody || test x"${RUN_AS_GROUP}" = xnogroup], [
+	AC_MSG_NOTICE([==========================================================])
+	AC_MSG_NOTICE([You have configured a build for default user '${RUN_AS_USER}' or])
+	AC_MSG_NOTICE([group '${RUN_AS_GROUP}' account names. This may be not safe.])
+])
+
 AS_IF([test x"${NUT_VERSION_DEPLOYED-}" = x"<reenter>"], [
 	AC_MSG_NOTICE([==========================================================])
 	AC_MSG_NOTICE([You have configured a build for "in-place" replacement])